From the top of a tower of height `200 m`, a ball `A` is projected up with `10 m s^(-1)`. And `2 s` later another ball `B` is projected vertically down with the same speed. Then

Options

A. Both A and B will reach the ground simultaneously
B. Ball A will hit the ground 2s later than B hitting the ground
C. Both the balls will hit the ground with the same velocity
D. Both the balls will hit the ground with different velocity

Answer

A, C

Explanation

Ball A will return to the top of tower after ` T=( 2u)/(g) =(2xx 10 )/( 10 ) 2s ` with speed of `10 ms^(-1) ` downward.And this time, B is also projected downwards with ` 10 ms^(-1) ` so both reach ground simultaneously. Also they will hit the ground with the same speed..